Effect Of Thermal Process On Connective Tissue From Jumbo Squid Mantle

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Food
Chemistry
Food Chemistry 107 (2008) 1371–1378
www.elsevier.com/locate/foodchem

Effect of thermal process on connective tissue from jumbo
squid (Dosidicus gigas) mantle
´
´
Adriana Zulema Valencia-Perez a, Miriam Hiessu Garcıa-Morales a,
a
b
´
´
´
´
´
Jose Luis Cardenas-Lopez , Jose Ronaldo Herrera-Urbina , Ofelia Rouzaud-Sandeza,
a,*
Josafat Marina Ezquerra-Brauer
a

´
Departamento de Investigacion y Posgrado en Alimentos (DIPA), Universidad de Sonora, Hermosillo, Sonora, Mexico
b
´
´
Departamento de Ingenierıa Quımica y Metalurgia, Universidad de Sonora, Hermosillo, Sonora, Mexico
Received 23 June 2007; received in revised form 24 September 2007; accepted 26 September 2007

Abstract
The effect of twothermal treatments (fast freezing at À40 °C and vapor cooking at 100 °C) on connective tissue extract (CTE) from
jumbo squid (Dosidicus gigas) was investigated. Samples of CTE frozen at À40 °C were taken at 0, 3, 5 and 12 min. Also CTE was
cooked at 100 °C and samples were taken at 0, 1, 2.5 and 5 min. Light microscopic observations of CTE after 12 min of freezing showed
rupture of fibres. The CTEfibres showed agglutination during cooking time. The CTE insoluble fraction increased with freezing and
cooking time. Maximum zeta potential value of untreated CTE was detected at pH 5.0 at +30 mV, meanwhile in the frozen CTE it
was detected at pH 7.0 at +30 mV and two peaks (at pH 5.5 and 9.0) were observed at +20 mV in the cooked CTE. One endothermic
peak was found at 105.9 °C in the untreatedCTE, while in the frozen and cooked CTE the endothermic peaks were found at lower temperatures and enthalpies. Electrophoresis analysis of untreated CTE showed three bands. In the frozen CTE two bands appeared above
200 kDa, and in the cooked CTE, a 45 kDa band disappeared. These results suggest that during freezing and cooking processes there
were modifications to molecular bonds that hold theintegrity of the structure of the connective tissue of the jumbo squid mantle.
Ó 2007 Elsevier Ltd. All rights reserved.
Keywords: Connective tissue; Jumbo squid; Mantle; Thermal denaturation

1. Introduction
Jumbo squid (Dosidicus gigas) is a cephalopod found in
´
abundance off the Pacific coast of Mexico (Martınez-Agu´
´
ilar, Morales-Bojorquez, Dıaz-Uribe, Suarez-Higuera, &
´Hernandez-Herrera, 2004). Although the growth of the
fishery in Mexico has been spectacular, great contrasts

Abbreviations: CTE, connective tissue extract; SSF, salt-soluble fraction; ASF, acid-soluble fraction; IF, insoluble fraction; DSC, differential
scanning calorimetry; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
*
Corresponding author. Tel.: +52 662 259 22 07; fax: +52662 259 22
08.
E-mail address: ezquerra@guayacan.uson.mx (J.M. Ezquerra-Brauer).
0308-8146/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.foodchem.2007.09.060

have characterized this fishery. The local fishing and processing efforts are not supported by appropriate management or technological processes. Therefore, the local
fisheries are at a disadvantage whentrying to compete
´
for better markets (Luna-Raya, Urciaga-Garcıa, Salinas´
Zavala, Cisneros-Mata, & Bletran-Morales, 2006).
Jumbo squid is normally sold in the form of frozen or
cooked frozen gutted mantle (Luna-Raya et al., 2006).
However, freezing and cooking can affect the functional
properties of the proteins resulting in changes on the rheological properties (Ando, Ando, Tsukamasa,Makinodan,
& Myoshi, 1999; Badii & Howell, 2002; Paredi, Roldan,
& Crupkin, 2006), which alter the texture and eating quality of seafood, thereby causing wastage of a scarce and rich
protein source (Paredi et al., 2006). Thus, the proteins and

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A.Z. Valencia-Perez et al. / Food Chemistry 107 (2008) 1371–1378

their functional properties are modified in a manner determined by the...